Cup fob roller-bearings and process of making same



I H. H. TIMKEN. CUP FOR ROLLER BEARINGS AND PROCESS OF MAKING SAME.

. APPLICATION FILED JUNE 29. 191B 1 28,225 Patented Dec. 30, 1919.

HENRY H. TIMKEN, or cn v'ron, OHIO.

CUP FOR ROLLER-BEARINGS AND PROCESS'OF MAKING- SAME.

To all whom it may concern:

Be it known that I, HENRY H. 'TIMKEN, a citizen of the United States,and a resident of the city of Canton, in the county of Stark and-Stateof, Ohio, have invented a new and useful Improvement in Cups forRoller-Bearings and Processes of Making Same, of which the following isa specification.

My invention relates to a process of manufacturing cups for conicalrollerbearings,

whereby much skilled work, much waste .of material and much loss ofproduct due to inaccuracies and distortions occasioned by heat treatmentor by insufficiently accurate .work- The principal objects of thepresent invention are to simplify the process of manufacturing conicalbearing cups, to reduce the cost of manufacture, and to minimize thedanger of distortion in the heat treatment.

In the accompanying drawing, which forms part of this specification, andwherein like symbols refer to like parts wherever they occur,

Figure 1 is an end view of a cylindricaltube constituting the stock fromwhich the bearing cup is formed;

Fig. 2 is a side view of the tube, with dotted lines indicating wheresections or rings are to be out therefrom;

Fig. 3 is a side view of one of said sections or rings;

Fig. 41s a vertical sectional view of the die with the section or ringin initial position therein and with the punch shown in side elevationand in raised position;

Fig. 5 is a vertical sectional view through the die, punch, and cup orring showing the punch at the downward limit of its strokef Fig. 6 is asectional view of a finished cup or ring of varying thickness Fig. 7 isa view of a blank for the cup in the form of a straight flat strip orribbon;

.Fig. 8 is a cross-section of a ring formed out of the blank shown inFig. 7

Fig. 9 is a View of a; blank in the form be an arucate flat strip orribbon; and

Fig. 10 is a cross-section of a ring made out of the blank illustratedin Fig. 9.-

According to the present invention, it is preferable to start with aseamless tube A of drawn steel of cylindrical section. This tube is cutinto short lengths or rings A of approximately the length of thefinished cup, or a little less. Both the inner and the outer simplyfinish the Specification of Letters Patent. Patented Dec. 30, 1919. IApplication filed .Tune 29, 1918. Serial No. 242,606.

ter very slightly less than required and then.

same by broaching in a press. v 1

At this stage of manufacture, the ring A is a cylinder; and the nextoperation is to convert this cylinder into a true conical cup with itsinner and outer surfaces concentric. This result can be accomplishedeither by expansion or by contraction of the cylinder, the latter beingpreferred. For the purpose of contracting the cylinder into a cone, thecylindrical ring A is forced endwise in a strong tapering die C whoseoperative inner surface 1 is of conical form and of a diameter whichranges from a little more than the overall diameter of the ring at theto of the die to the overall diameter of the nished cone at the bottomof the operative-surface of the die, at which point the diameter of thedie opening is abruptly decreased, thus forming a shoulder 4L.

Mounted on or integral with the plunger D, which applies the force tothe end of the ring, is a mandrel 3 arranged in axial aline ment withthe die and whose exterior-surface-is a cone of the size and inclinationof the interior of the finished cup. When the ring A is placed in thedie and pressure applied thereto by means of the plunger, the

die. This operation contracts the diameter of so much of the ring ascomes in contact with the innersurface. of the die, so as to conform theouter surface of the ring to the inner surface of the die; and at thesame time, the inner surface of the ring is made I to conform to theouter face of the mandrel.

The cup is loosened from the die by a suitable knock-out E.

The progressive movement of the ring in Wardly of the die continuesuntil it brings up against the shoulder; and its further for- Wardmovement being thus prevented, the continued pressure of the mandrelcauses the metal to flew sodas-to fill all void space between thesurface of the lower portion of the die and the corresponding surface ofthe mandrel.- While the inner surface of the die and the outer surfaceofthe mandrel the pr have a common axis, it ispreferable that theinclination of the inner surface of the die should be less than theinclination of the outer surface of the mandrel; in which case, theresulting cup A must be thicker at its small end than at its large end.The surfaces of the cup A are accurately enough finished by, thisdie-shaping operation to make it unnecessary to do further Work on thembefore hardening or carbonizing. The inclination of the die is such thatthe outer surface of the cup will have a. taper equal to the angle of reose of the cup metal for the metal with which the cup will be in contactwhen in use; that is to say, the inclination of the outer surface issuch that when the cup is'in place there will "be a tendency for it tojam into its retaining member rather than to loosen. In the case of cupsdesigned for use in motor vehicle axle bearings, the outer surface ofthe cups will have an inclination equal to the angle of repose of thecup metal for ordina hub metal.

The next step is to carbonize the cones or cups in the usual manner orsubmit them to any of the usual heat treatments for the purpose ofhardening them. As these conical cups are of circular section, thetendency is for them to distort very little, if any, during the heattreatment and the form of the cup makes it a simple matter to correctmiriorirregularities arising from warping. Consequently, there ispractically no loss of not due to the heat treatment,'and very little,if any, occasion to grind the hardened surface. In other words, thegrinding operation heretofore commonly required may be dispensed withentirely.

fill

The principal advantage in contracting the ring, rather than expandingit, is that the contraction avoids the severe tensile stress that mightdisrupt the wall. Besides, the operation of the contracting is betteradapted for rectifying any unevenness in the thickness of the wall andit tends to make the metal more compact.

While it is preferable to start with tubing, it is practicable to startwith sheet metal. F011 this purpose, a blank may be made in the form ofa straight flat strip B having one end notched and the other end pointedconformabl to the'notch, as illustrated in Fig. 7, or the blank may bein the form of an arcuate strip F with one end notched and-the other endpointed to conform to said notch, as illustrated in Fi 9. In the case ofthe flat strip, it is rol ed into a cylin drical ring B with its pointedend fitting into the socket end, as illustrated in Fi 8; and in thecaseof the arcuate strip, it is likewise rolled into the form of aconical ring F as illustrated in Fig. 10. It is preferable to accuratelyfinish both surfaces of the straight and arcuate strips before they arerolled into the cylindrical rings. So

long as the ends of the sheet metal blanks are initially brought intocontact or close proximity, they may be treated the sameas the closedring or section tubing, as hereinbefore described. During thistreatment, the enormous pressure to which they are subjected causes acircumferential strain that produces a perfect fitting of the ends sothat, 1n the resulting product, the surface is almost as smooth anduninterrupted as if the metal was continuous at the joint. One advantageof this feature is that the cup is enabled to spring under unusualconditions where a solid ring would be likely to fail. This rolledconical shell may be carbonized before or after treatment in the tapereddie and can be hardened after such treatment but the hardening processcan be done in tapered dies with suitable fiutings for admission ofquenching fluid but havin these flutes of proper taper to hold thefinished cup in close approximation to exact desired finished shape.

What I claim is: v

1. The process of makin conical cups for roller bearings which consistsin forming a ring with a cylindrical bore, finishing the cylindricalrings of approximately even thickness, finishin the inner surface ofsaid rings and then die-shaping said rings into conical cups with wallshaving an inside and outside surface approximately concentric buthaving' said surfaces with different degrees of taper.

3. The process of making conical cups for roller bearings which consistsin forming a ring, reaming the bore thereof to a cylindrical surface andthen forcing said ring endwise of a conical die by means of a conicalmandrel concentric therewith but of greater inclination, whereby theinner surface of the cup acquires the proper inclination for a bearingsurface for the rollers and the outer surface of the cup acquires aninclina tion adapted to produce a wedging action of said cup in itsmounting.

l. The process of making conical cups for roller bearings which consistsin finishing the surface of a strip of sheet metal, rolling said stripinto the form of a ring and then die-shaping said ring intoa conicalcup.

5. The process of makng conical cups for roller bearings which consistsin finishing the surface a of an arcuate strip of sheet metal, rollingsaid strip into a ring and then die-shaping said ring into a conicalcup.

6. The process of making conical cups for roller bearings which consistsin bending a emmas strip of sheet metal into a ring and forcing saidring with a conical mandrel endwise into a taper-die.

7. The process of making conical cups for roller bearings which consistsin finishing the surface of a fiat strip of sheet metal, bending saidstrip into a ring with the finished surface inside, forcingsaidring'with a mandrel ofthe inclination desired'for the bearing surface ofthe cup into a taper-die: of the lesser inclination desired. for theouter surface of the cup, the pressure being sufficient to make themetalfill the annular space between the mandrel and the die.

.8. A cup for a conical roller bearing comprising an inner bearingsurface having an v inclination suitable for cooperation with thebearing rollers and an outer bearing surface having an inclination lessthan its angle of repose for ordiary hub metal.

9. As a new article of manufacture, a

conical cup for roller bearings resulting from the contraction of acylindrically reamed ring in a slightly tapered die by a taper mandrelof greater inclination with ressure suflicient to make the metalcompletely fill the annular space between the mandrel and the die, I r

10. As a new article of manufacture, the cup for conical roller bearingsresulting from the operation of a conical mandrel on a strip of metalrolled into a ring in a taperdie under sufficient pressure to make themetal fill the space between the mandrel and the die. I

11. A split cup for conical roller bearings resulting from the operationof a conical mandrel against a split ring in a conical die underpressure sufiicient to make themetal fill the*void space betwen themandrel and the die.

Signed at Canton, Ohio, this th day of June; 1918. HENRY H. TIMKEN.

